Neosporosis is caused by the protozoan parasite Neospora caninum. Neosporosis has been recognized in dogs, cattle, horses, and other animals, but the dog is the definitive host. Infection is uncommon but can be acquired by ingesting contaminated food and water, or ingesting infected tissues. It may also be transferred from a mother to a fetus still in the womb (transplacentally).

Severe neosporosis infections tend to occur in puppies.

Both puppies and older dogs may be affected. Most severe infections occur in young puppies, which typically develop paralysis of the legs, particularly the hind legs. The paralysis is often progressive and results in rigid contracture of the muscles. In some dogs, only neurologic signs (such as inflammation of the brain and spinal cord) are seen. Disease of the peripheral nerves and spinal nerve roots appears typical of neosporosis. Skin inflammation with sores, inflammation of the liver, pneumonia, and inflammation of the brain may also occur. If not treated promptly, death is likely.

Your veterinarian will recommend proper antibiotic treatment. There is currently no vaccine.

Last full review/revision July 2011 by Otto M. Radostits, CM, DVM, MSc, DACVIM (Deceased); David A. Ashford, DVM, MPH, DS; Craig E. Greene, DVM, MS; Eugene D. Janzen, DVM, MVS; Bert E. Stromberg, PhD; Max J. Appel, DMV, PhD; Stephen C. Barr, BVSc, MVS, PhD, DACVIM; J. P. Dubey, MVSc, PhD; Paul Ettestad, DVM, MS; Kenneth R. Harkin, DVM, DACVIM; Delores E. Hill, PhD; Johnny D. Hoskins, DVM, PhD; Jodie Low Choy, BVMS; Barton W. Rohrbach, VMD, MPH, DACVPM; J. Glenn Songer, PhD; Joseph Taboada, DVM, DACVIM; Charles O. Thoen, DVM, PhD; John F. Timoney, MVB, PhD, Dsc, MRCVS; Ian Tizard, BVMS, PhD, DACVM